I'm certain you can infer the conversation that led to this email

Mom –

Why do you keep brining up conversations we had two years ago, or ten years ago? Were those conversations the defining moments of our relationship? You told me you don’t want to be like your mother and grandmother, who keep bringing up slights from decades ago, yet you consistently use these conversations as evidence against me. Don’t you want to get beyond that?

It isn't a third of what I want to say, but one thing at a time. God, you know, I keep thinking our relationship is getting better, but every time there's a little bit of tension, she turns right back into the self-righteous bitch I so desperately wanted to get away from 15 years ago. She's way too intelligent to not know what she's doing, and maybe that's the worst of it.